Replacing fish oil with pre-extruded carbohydrate in diets for Atlantic salmon, Salmo salar, during their entire marine grow-out phase: effects on growth, composition and colour.

摘要

Effects of replacing fish oil in Atlantic salmon (Salmo salar) feeds with pre-extruded carbohydrate (wheat, corn or pea) for the duration of marine grow-out were investigated upon growth, colour and composition. Growth rate, condition factor, carcass yield and hepatosomatic index varied with season but were unaffected by carbohydrate source. Condition factor was further influenced by fish size and/or dietary lipid content and was negatively correlated with carcass yield. Dietary lipid content, rather than carbohydrate source, was also responsible for differences in flesh colour, pigmentation and fillet fat content among treatment groups. It is suggested that use of pre-extruded carbohydrates as a cost effective substitute for lipids in Atlantic salmon feed is limited.